Manufacture of paint



Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE No Drawing. Originalapplication December 28,

1935, Serial No. 56,585. -Divlded and this application May 7, 1937,Serial No. 141,241

Claims.

The present application is a division of my copending application SerialNo. 56,585, entitled Method and process of converting non-aqueous p pThe present invention relates to a process for incorporating finelydivided solids into vehicles which may form a part of ultimate consumerproducts. The process achieves a fine subdivision of the'finely dividedsolids and their substantially uniform and complete dispersion into thevehicle, while eliminating the customary grinding of such solids intothe vehicle.

Finely divided solids dispersed in a dispersion medium to form a pulphave an individual particle size and a completeness of dispersion whichis very desirable to maintain in the consumer product. The dispersionmediums which act best as pulping mediums for finely divided solids aremobile liquids. I'he formation of pulps of finely divided solidsdispersed in a mobile pulping medium of an aqueous liquid has heretoforebeen suggested. The use of such aqueous pulps and their incorporationdirectly into the commonly utilized vehicles has not been satisfactorybecause such vehicles usually are less mobile than such pulping mediumsand are immiscible therewith. The presence of the aqueous liquid in thepulp thus tends to impair the quality and completeness of the dispersionand is not practical from the commercial standpoint because of thedifliculties inherent in removing the water from the completeddispersion. I have found that mobile liquids of a non-aqueous nature maybe used in forming the initial pulp. Such pulps may be formed from pulpsin which the pulping medium is an aqueous liquid or the solid particlesmay be pulped directly into the non-aqueous mobile liquid as the pulpingmedium.

In the present process, therefore, I propose to utilize the desirableproperties of the pulp form of finely divided solids in a mobilenon-aqueous pulping medium which is relatively more volatile than thevehicle into which the solids are to be incorporated in the process. Byso doing it is possible to secure dispersion of the finely dividedsolids directly into the vehicle without grinding the solids in thevehicle. The pulping mediums which may be used satisfactorily in thepresent process are chiefly mobile liquids of a non-aqueshould beselected which has a surface tension lower than the surface tension ofthe final dispersion medium and one whitth has a preferential affinityfor the finely divided solid particles, so that the pulping medium actsas an efficient wetting agent for the finely divided solids. Among suchpulping mediums are liquids in the I field of organic solvents, such,for example, as toluene, benzene, acetone, turpentine, and the like. Theuse of such pulping medium will be found to preserve the beneficialfeatures of the pulp formed of finely divided solids in a mobile 1pulping medium in such a manner as actually to facilitate the transferof the finely divided solids to the final dispersion medium which may bethe vehicle of a consumer product.

Thus one of the objects of the present invention is to utilize thenon-aqueous pulp form of finely divided solids in the art ofcompounding.

It is well known that finely divided solids are now combined in a directmanner with other elements I in which combination these finely dividedsolids are the necessary and desired constituents. A great number ofvarious types of mechanical devices are employed by chemicalmanufacturers in the preparation of such combinations, and it is mypurpose to disclose a process and method whereby these finely 'dividedsolids in pulp form may be more readily and advantageously combined withsuch products, in order thereby to simplify such processes, while at thesame time producing superior products inasmuch as these 3 finely dividedsolids will be more uniformly distributed in such products by thepresent process than by previously knownprocesses.

It is a further object of the present invention .to provide a method forconverting non-aqueous pulps of finely divided solids and to displace orreplace either wholly or partially the non-aqueous pulping medium ofsuch pulps by other constituents or vehicles of the desired product. Inother words, to disclose a process adapted to the 40 incorporation offinely divided solids such as abrasives, fillers, colors, and the like,into products useful as and/or in the manufacture of adhesives,insecticides, leatherJeather finishes, artificial leather, printing ink,soap, candles, cosmetics, lubricants, rubber goods, tires, paint, paintenamels, matt varnishes, varnish stains, oil stains, putty, woodfinishes, metal finishes, flatting compounds, polishes, floor wax,sealing wax, coating compositions, thermoplastics, molding compounds,plastics, Celluloid, lacquer, oilcloth, linoleum, etc.

In a preferred embodiment of the present invention, a further object isto disclose a method of replacing the volatile pulping medium of thefinely divided solids in pulp form in its vapor phase under atmosphericpressure, increased pressure, or diminished pressure (vacuum), by anon-volatile constituent, the latter constituent being a component alsoof the final and/or consumer product. Such preferred embodiment consistsin general in the transformation of the solids of non-aqueous pulpshaving a volatile pulping medium into non-volatile constituents,vehicles, or composites.

Further and additional objects of the present invention will morereadily appear in the perusal of my specification and examples.

While the present process possesses economical advantages over presentmethods, the product made in accordance with my teachings is ofexcellent quality and derives a distinctive and pleasing appearanceand/or superior effectiveness from the uniformity and evenness of sizeand dispersion of the-finely divided solids, whether abrasive, color orfiller, from the nature and characteristics of the parent pulps having anonaqueous volatile pulping medium. This mark of uniformity ofappearance and superior effectiveness which didtinguishes the individualbatch or run may be found in any number of successive batches or runs.Thus variations of or in manufacture may be substantially eliminated bythe present process which excludes to a large extent the human elementand substitutes therefor a control of the process based on the physicalconstants of the volatile pulping medium as well as the relativelynon-volatile replacing or displacing constituents.

The quality of the above-enumerated products depends largely upon thefinenessof their incor-- porated solids and to a even greater extentupon their even distribution in their vehicles. It is technically fareasier to obtain pulps of these solids when the pulping medium is avolatile mobile liquid in which the solids possess a high degree offineness, than in an oil or heavy viscous or plastic vehicle. Therefore,I have selected and desire to employ these solids in their pulp form,preferably utilizing non-aqueous pulping mediums of a relativelyvolatile nature. This is distinguishable over present manufacturingmethods which utilize the finely divided particles in the dry state. Ihave discovered that such a pulping medium may be displaced or replacedby a nonvolatile behicle incorporating the solid constituv ents of suchpulps by applying this principle of replacement or displacement in mynovel process Y to obtain a most even and uniform distribution of saidsolids into the vehicle.

A further object which will appear clearly from my specification andexamples is to disclose, as one method, whereby this displacement orreplacement of the non-aqueous volatile pulping medium by a non-volatileconstituentof the product may be accomplished, a'distillation methodunder atmospheric pressures or vacuum and/or increased pressures, eitherwith or without the use of agitation and in the presence of non-volatilereplacing or displacing constituents or vehicles.

For the purpose of clarifying the terms used herein, I hereby definepulps as being any soft or semi-liquid mixtures of solid particles inliquids, the liquids being hereinafter referred to as the pulpingmediums.

By the use of the term non-aqueous I intend to include substanceschiefly of an organic nature which are substantially free of water orexclude the substances which are chiefly of water or of an aqueousnature.

The term dispersion medium" as used herein includes substances forming acomponent element of the end or consumer product and which may existeither as a liquid or a plastic under the conditions existing at thetime of the volatilization of the non-aqueous pulping medium. Suchdispersion medium may exist under normal atmospheric temperatures andpressures, either as a solid or plastic such as a resin, or as a liquidsuch as an oil.

In order that the present invention may be more clearly understood andthe process of converting pulps of finely divided solids having anon-aqueous volatile pulping medium into compounds having non-volatileconstituents, it is essential that the non-volatile constituent mustdisplace or replace the volatile pulping medium and that this must beaccomplished at the same time that the finely divided solids areuniformly distributed throughout the non-volatile constituent orproduce. Any method whereby the non-volatile constituent or vehicle orproduct is caused to replace or displace the non-aqueous volatilepulping medium falls within the scope of the present invention andclaims, but in a preferred embodiment thereof I employ distillation andin some cases distillation and agitation. I may so control thisconversion that as the volatile pulping medium is driven off, thenon-volatile constituent replaces the same in such manner as to assurethat the finely divided solid is evenly and uniformly distributed intothe non-volatile constituent or vehicle.

The following examples are illustrative of the operation of my'inventionand processes and are here included for such purpose and not for thepurpose of limitation.

Example I In order to make "Prussian Blue in Oil I proceed as follows:100 lbs. of toluene Prussian blue pulp of 30% pigment content is mixedwith 30 lbs. of linseed oil. This mixture is then subjected todistillation and agitation until the '70 lbs. 01' toluene of thePrussian blue pulp are distilled off.

In practice I prefer to employ a kneading machine of the type of Werner& Pfleiderer or other suitable type which is provided with a jacket,hollow agitating blades, a tight cover, a still neck, an attachedcondenser, an inlet valve which permits feeding for continuousoperation,and thermometer wells for measuring the temperatures of the machinecontents as well as the vapor in the still neck. In such an apparatusdistillation may proceed under atmospheric pressures or under eitherincreased or diminished pressures. In-

to such apparatus I place 1000 lbs. of Prussian blue toluene pulp of 30%pigment content and 300 lbs. linseed oil. The blades revolve at a speedof 60 R, P. M. The cover is tightly closed and connected with the stillneck and condenser which in turn are tightly connected with a 300-gallon receiver and the latter joined with a vacuum creating source. Thetemperature of the mix is now raised to C. by means of suitable meanseither in the jacket or in the hollow blades. While this batch isagitated by the blades which exeri a smearing or kneading or squeezingaction, thi vacuum line is opened and a vacuum of 25 to 2'. inches ofmercury is created inside the apparatus. Under these conditions thetoluene is distilled off and there remains in the apparatus 60( lbs. ofPrussian Blue in Oil" (in this case linsee amaaea oil) which may bedischarged through a valve in the bottom or by tilting or any otherconvenient means.

Example II For making Chrome Orange in Japan, I place in the apparatusof Example I, 1000 lbs. of 50% basic lead chromate acetone pulp and 500lbs. of Grinding Japan" and distill oi the acetone.

I may in a similar way, proceed to convert the fillers or pigments orabrasives necessary in the production of any of the products outlinedabove or other similar consumer products or intermediate products.

In the foregoing examples of processes embodying the present invention,it will be noted that in each instance a pulp of the finely dividedsolids in a non-aqueous pulping medium, which is relatively morevolatile than the dispersion medium, is admixed with thedispersion'medium and is then volatilized and dissociated from themixture, whereupon the finely divided solids are transferred to andsuspended in the dispersion medium. In each instance the pulping mediumis compatible with or miscible in the dispersion medium prior to itsvolatilization and removal from the admixture.

By the term Grinding Japan as used herein is meant a varnish of the typecommonly used in Japanning" of metal or wooden articles and which isalso used as a vehicle into which pigments may be ground by conventionalgrinding processes. I

While I have named particular substances for particular purposes in theforegoing examples, I do not wish to be limited thereby to theutilization of such substances or such purposes as the present processis adaptable to many other purposes, using many substances other thanthose particularly specified.

I claim:

1. The process of manufacturing paint which includes the steps ofproviding a suitable quantity of a substantially water-free finelydivided pigment pulped in a substantially water-free volatile thinnerfor the paint vehicle and which has a greater wetting action on thepigment than does the said vehicle, admixing a suitable portion of aselected non-volatile paint vehicle therewith, placing the admixedpigment, thinner and vehicle in a still, subjecting said admixture inthe still to simultaneous heating and kneading to distill ofi apredetermined amount of said thinner while retaining the pigmentparticles in finely divided condition and substantially uniformlydispersed in the mass, whereby the excess thinner is removed and theadmixture is concentrated with the pigment particles dispersed in saidvehicle and any remaining thinner.

2. The process of manufacturing a blue colored paint which comprisesadmixing a substantially water-free toluene pulp of Prussian bluepigment with linseed oil, thereafter simultaneously kneading the mixtureand distilling off a predetermined amount of the toluene whilemaintaining the pi ment particles in a dispersed condition, whereby theconsistency of the composition is increased and the Prussianblue'pigment is dispersed in the linseed oil and any remaining tolueneas the vehicle of the coating composition.

3. The process of manufacturing an orange colored paint which comprisesadmixing a substantially water-free acetone pulp of basic lead chromatewith Grinding Japan, and thereafter simultaneously kneading the mixtureand distilling off predetermined amounts of the acetone whilemaintaining the pigment particles in a dispersed condition, whereby theconsistency of the composition is increased and the basic lead chromateis dispersed into the said Grinding J apan" and any remaining acetone asthe vehicle of the coating composition.

4. A method of incorporating pigment into a paint vehicle by kneadingthe mass, which comprises admixing thepigment, a substantiallywater-free volatile wettingagent therefor, and a substantiallywater-free paint vehicle miscible with the said wetting agent, to form amixture in which the pigment is thoroughly wetted by the agent andvehicle, thereafter distilling off a desired amount of the wetting agentand kneading the mass simultaneously during said distillation, whereby.the consistency of the mass is increased and the pigment is uniformlydispersed in the

